This invention relates to a water flow control valve and diffuser for flow proportioning and for distributing water from a point source to a water basin in a single integral valve and diffuser unit.
Among the problems associated with prior water valve designs and distribution system arrangements for cooling towers is that uniform water distribution to the fill assembly area is seldom achieved in practice. In practice, generally one flow control valve is used in each hot water basin with the valve being located near the center of the basin. The water leaving the valve enters a diffusion box which is normally below the valve discharge. The purpose of this diffusion box is to decrease the water velocity and to redirect flow radially outward in the hot water basin. In the prior art, no positive means was provided in the diffuser box or valve design to proportion and direct the flow for uniform distribution from a point source to a rectangular water basin. Consequently, localized eddies, high velocity crosscurrents and wave action typically occurs within the basin resulting in poor water distribution. Prior valve and diffuser box arrangements also have relatively high hydraulic friction losses thereby requiring more pumping energy than desired.
Furthermore in U.S. Pat. No. 3,875,269 issued on Apr. 1, 1975, to Ecodyne Corp., there is described a cooling tower distribution box. This box, however, differs from applicant's in that the water is not positively proportioned and redirected and does not flow out smoothly from the distribution box. Also, in the valve in U.S. Pat. No. 3,875,269 water is directed against an upper shroud wherein the water is then forced or directed down into a distributing box where ribs and baffles direct the water outward to the pan section. There is much friction loss and inconvenience and small flows of water are not equally distributed since the water first hits the covering shroud to dissipate flow energy before it is directed to the distributing means.
In applicant's case, as the cylinder portion of the valve is lifted off its seat even a small amount of water will flow smoothly through the equalizing baffles and be distributed to the pan section.
Also, the typical conventional distribution boxes used in the prior art have included a honeycomb type wood structure to receive the splashing water and distribute it under its outer edges across the hot water basin. These boxes have tended to be very large and have many parts which are time consuming to erect. A large pressure drop also is present across these boxes which causes pumping and distribution problems. Being constructed of wood these boxes do not offer good resistance to corrosion and, therefore, require frequent maintenance.
The primary object of this invention is to provide a water flow control valve and diffuser for a crossflow cooling tower which provides a positive means for controlling, directing, proportioning and diffusing water from a point source to a rectangular hot water basin with the flow control function and the proportioning and redistribution functions all accomplished in a single, integral unit.
A further object of this invention is to reduce the hydraulic friction losses and internal forces acting on the working parts of the valve.
A still further objective is to provide a valve which contains means for a positive shut off of water flow.
A still further object is to provide a crossflow cooling tower water flow control valve and diffuser which is constructed mainly from plastic parts and thereby offers resistance to corrosion and which is simple and economical to construct.